The invention relates to a method for checking the functionality of a switching center which is to be tested, can be used to produce subscriber connections in a telecommunications network and has at least two switching connections to which switching centers can be connected and in each of which an intermediate interface is provided for interchanging user information on the subscriber connections with a respectively connected switching center, and has at least one signaling interface via which signaling messages for controlling the subscriber connections and for administration of the intermediate interfaces are interchanged, with each signaling message having details relating to its source and destination switching center.
The invention also relates to a device for checking the functionality of a switching center, which is to be tested, for producing subscriber connections in a telecommunications network.
The invention relates in the same way to a switching center which can be used to produce subscriber connections in a telecommunications network and has at least two switching connections to which switching centers can be connected and in each of which an intermediate interface is provided for interchanging user information on the subscriber connections with a respectively connected switching center, and has at least one signaling interface via which signaling messages for controlling the subscriber connections and for administration of the intermediate interfaces are interchanged, with each signaling message having details relating to its source and destination switching center.
Telecommunications networks, in particular telephone networks, have switching centers which are networked with one another and are used for setting up and maintaining call collections between the subscribers in a network. The switching centers in modern telecommunications networks are automated devices which comprise a number of components, for example one or more switching networks, a central controller, line trunk groups, etc. Switching centers communicate with one another by means of specific inter-exchange signals for controlling and monitoring the switching processes and the services carried out, and for administration of the connections and connecting lines. Usually, these signals are interchanged in the form of signaling messages which are interchanged between the switching centers via dedicated channels, which are not the same as the user channels, and whose form depends on the respectively used protocol. One example of such an inter-exchange protocol is the so-called Signaling System No. 7 or, in short, CCS7 (xe2x80x98Common Channel Signaling System No. 7xe2x80x99) in accordance with International Telecommunications Union (ITU) standards Q.700 to Q.716. In CCS7, the interchanging of signaling messages is associated with a dedicated central channel network.
Owing to the stringent requirements on a switching center during operation, the switching functions must be checked before the switching center is brought into use, expediently even before the switching center device is linked to the network, in order to avoid any risk of a serious adverse effect on network operation from the start, or even before the switching center is delivered. The realistic testing of a switching center means that the switching center which is to be tested must be embedded in a network environment which is sufficiently large to satisfy the test requirements. Since it is impossible to embed the switching center in a real network during the checking process, the networkxe2x80x94to be more precise the partner switching centers connected to that switching centerxe2x80x94must be simulated by test equipment. This test equipment is in each case used to simulate one or more partner switching centers. However, in order to simulate a realistic network, for example a network having several hundred to thousand switching centers, a very large number of test equipment items would thus be required, which it has not been possible to provide because of the costs associated with this, and control difficulties. Thus, in the past, realistic tests have not normally been carried out in large network configurations.
The object of the invention is to allow a realistic check of the functionality of a switching center using simple means and with the capability to control the switching center in a simple manner and, in particular, with it being possible to simulate an extensive network.
The object is achieved by a method of the type mentioned initially in which, according to the invention, original signaling messages which have been transmitted from the switching center which is to be tested and in which the switching center which is to be tested is stated as the source point are received, the original signaling messages are each converted in accordance with a first predetermined rule into signaling messages in which the switching center which is to be tested is stated as the destination point, and the signaling messages which have been converted in this way are sent to the switching center which is to be tested.
This solution solves the set object in a simple manner and, in particular, there is no need to provide a number of test equipment items and to connect them to the switching center which is to be tested.
In one preferred embodiment of the method according to the invention, in order to reduce the number of signaling interfaces, the converted signaling messages are each sent to the switching center which is to be tested via that signaling interface via which the associated original signaling message was received.
Advantageously, a switching center which is uniquely associated with the destination point of the associated original signaling message is stated as the source point in each of the converted signaling messages.
In this case, it is expedient for a clearly understandable test operation for the switching centers which are stated in the signaling messages to be associated with one another in pairs and for the switching center which is associated with the destination point of the original signaling message to be stated as the source point in the converted signaling message.
For simple implementation of the associated pairs, it is in this case advantageous for the addresses of the mutually associated switching centers to be determined from one another by means of an inversion operation.
It is furthermore expedient for simple implementation of a test layout for each of those intermediate interfaces which are logically associated with mutually associated switching centers to be looped through.
The invention has been found to be particularly advantageous if the signaling interface is connected to a signaling network which is independent of the intermediate interfaces since, in this case, separate handling of the interfaces can be utilized.
In order to allow both associated and quasi-associated signaling processes to be tested, it is possible, in a further advantageous embodiment, in addition, for signaling messages, in which source and destination points which differ from the switching center which is to be tested are stated, to be produced and to be sent to the switching center which is to be tested, and for signaling messages, which have been transmitted from the switching center which is to be tested and in which source and destination points which differ from the switching center which is to be tested are stated, to be received and to be checked to determine whether they match previously sent signaling messages.
Furthermore, the object stated above is achieved, based on a device for checking the functionality of a switching center which is to be tested, by a device having a signaling interface to which the switching center which is to be tested can be connected and which is set up for interchanging signaling messages between switching centers for controlling subscriber connections and for administration of the intermediate interfaces which connect the switching centers, with each signaling message having details relating to its source and destination switching center, having a device for transmitting and receiving signaling messages via the signaling interface or interfaces, and having a converter device whose output is supplied to the transmitting/receiving device and to which signaling messages which have been received by the transmitting/receiving device can be supplied, for conversion of original signaling messages in accordance with a first predetermined rule into converted signaling messages in each of which the source point of the original signaling message is stated as the destination point.
This device allows the testing of switching centers according to the invention, including their advantages as described further above.
One advantageous embodiment of the device according to the invention, which also allows the production and reception of signaling for conversion of signaling messages, contains a message source whose output is supplied to the transmitting/receiving device, in order to produce signaling messages in which source and destination points which differ from the switching center which is to be tested are stated, a message sink for receiving signaling messages and/or for evaluating them to determine whether they match previously sent signaling messages, and a discriminator device to which signaling messages which have been received by the transmitting/receiving device can be supplied, for assigning the signaling messages to subsequent devices which process messages, such as the converter device and the message sink, in accordance with a second predetermined rule, which differs from the first rule, using the contents of the relevant signaling message.
The object stated above is equally achieved by switching of the type described initially, which has a converter device for conversion of original signaling messages in accordance with a first predetermined rule into converted signaling messages in each of which the source point of the original signaling message is stated as the destination point, and a rerouting device for rerouting signaling messages which are to be sent as original signaling messages from the signaling interface to the converter device, and for rerouting signaling messages which have been converted in the converter device as signaling messages which arrive at the switching center to the signaling interface.
This solution allows the switching to be tested without the use of any additional equipment, and once again with the capability to achieve the advantages mentioned further above.
One particularly advantageous embodiment of the switching according to the invention, which also allows simulation of the production and reception of signaling, contains a message source whose output is supplied to the rerouting device for producing signaling messages in which source and destination points which differ from the switching center which is to be tested are stated, a message sink for receiving signaling messages and/or for evaluating them to determine whether they match previously sent signaling messages, and a discriminator device to which signaling messages which have been rerouted by the rerouting device can be supplied, for assigning signaling messages to subsequent devices which process messages, such as the converter device and the message sink, in accordance with a second predetermined rule, which differs from the first rule, using the contents of the relevant signaling message.